Copper-based ATRP catalysts of very high activity derived from dimethyl cross-bridged cyclam

Autor:	Gary R. Weisman, Edward H. Wong, Wade A. Braunecker, Krzysztof Matyjaszewski, Samuel J. Brooks, Wei Tang, Nicolay V. Tsarevsky
Rok vydání:	2006
Předmět:	Acrylate Chemistry Atom-transfer radical-polymerization Process Chemistry and Technology Solution polymerization Catalysis Electron transfer chemistry.chemical_compound Reaction rate constant Cyclam Polymer chemistry Physical and Theoretical Chemistry Equilibrium constant
Zdroj:	Journal of Molecular Catalysis A: Chemical. 257:132-140
ISSN:	1381-1169
DOI:	10.1016/j.molcata.2006.05.031
Popis:	Dimethyl cross-bridged cyclam (DMCBCy) forms a very reducing CuI complex that possesses the highest known catalytic activity to date in atom transfer radical polymerization (ATRP) reactions. The value of the ATRP equilibrium constant in a reaction with methyl chloroacetate for CuICl/DMCBCy is 30-fold larger than for the very active catalyst CuICl/Me6TREN. The activation rate constant for the DMCBCy-based complex was also determined and is about 1.5 times larger than for CuICl/Me6TREN. The ATRP of n-butyl acrylate mediated by CuIBr/DMCBCy was fast even at 30 °C and yielded well-defined polymers when a sufficient amount (about 10 mol% of the total catalyst) of deactivator (CuIIBr2/DMCBCy) was added to the reaction mixture. Side reactions such as electron transfer from the very reducing CuIBr/DMCBCy to the electrophilic acrylate radicals most likely account for the observed limited conversions.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::076ca63b30281aa21881ace883228d6e https://doi.org/10.1016/j.molcata.2006.05.031 Zobrazit plný text záznamu Full Text from ScienceDirect